Method of and composition for inhibiting foaming in steam boilers



Patented Dec. 19, 1950 M OD OF POSITION FOR IN- nnsnnvo FOAMING IN STEAM Bomnns 7 Lewi 0- (iunderscn .P Rid 111., assignor to Dearborn Qhemi'cal Company, Chicago, 111., a

corporation of Illinois No Drawing, Application March 19, 1945;

Serial N0. 583,647

8 Cl ms; (01. 252-32 One feature of the present invention relates to the incorporation of redwood bark dust or alkali derivatives of redwood bark to boiler water, whereby the sludge in the boiler water is dispersed and/or solubilized and encr'ustation of boiler surfaces or formation of hard deposits of calcium or magnesium compounds is prevented or lessened.

Another feature of this invention relates to 2 becom s ntr ned w th the steam l a n the boiler.

I o her words. bubb e need o b e eu lar v table to aus bo e ie mins- The stabi t oi the bubbles need n e uch that t e bubbles last but a very few seconds after pass.- ing the plane of the water level indicated in the waterglass.

As disclosed and claimed in my above identia method and a composition for conditioning l0 fied patents and applications, I have invented wa r for the prevention of foaming in water, in methods for conditioning water for steam genpar icular, boiler Waters, having a tendency to eration by incorporating with said water from a fo m. Mor especially, the invention pertains race to twe y-five o fifty parts per million or to a composition and a method of the nature inmore of a surface-active predom n y hydmr die ted nvolving the addition. of a composition 15 phobic organi u nce comprising molecules selected from the group consisting of redwood each including a group of closely spaced interbark dust, an alkali derivative of red d bark connected hydrophilic radicals and a plurality of dust, an alkali derivative of redwood bark, and long unsubstituted hydrocarbon chains attached an alkali derivative of redwood bark fiber, for d p (Patent 2,323,551); 9 of the purpose of increasing the e'fiiciency and/or 2 0 face-active predominantly hydlophoblc Orgamfi the efncient lives of foam inhibiting composi- Substances represented y the formula tions such as those disclosed in my United States Patents No. 2,328,551 (issued September '7, 1943) l a and (issued January 9, in in represents gydrocarbon con y Copending pp c Serial 305,959 2 taining at least ten carbon atoms, R1 represents November 24, I at least one hydrocarbon chain containin at 12, 1942); 501,293 (filed selfitelnber 4, 4 least ten carbon atoms and X represents a radi- 504976 (filed September 27, 1943) now b cal selected from the group consisting of the N, doned; 560,899 (filed October 28, 1944); 568,202 H 09 and NHCQ'fadica1s; O r (filed December 14, 1944); 563,203 (filed Dceminantly hydrophobic surface-active organic subb 1 1944); 563,204 (filed December 4 44 stances comprising a plurality of spaced hydro- 568,2 5 (fi December 14, 82. filed philic nitrogen containing radicals intercon- D e b 14, 19 d 56 (filed. D em nected by carbon atoms and having a plurality ber 1944)- of hydrocarbon chains containing each at least A5 disclosed n the above nt fi ap ea- 35 eight carbon atoms attached severally to said nitions oa n o boiler water is t; s eemtrogen containing radicals (application, Serial men v thou ht, q iv l t an accumulation No. 305,959, now if. s. Fatent No. 2,442,768, issued of foam on top of the surface of the boilerwater. June 943 or 9f polyaikyigne poiyammes When steam is rapidly withdrawn from a boiler ing both primary amino groups and ll; least 0. 1 with resultant foaming, there is no water sursecondary amino ou a lat d with a higher face within the boiler correlated with the water level indicated in the conventional waterglass attached to the boiler. In other words, there is no sharp line of demarcation between solid water and foam in the boiler during rapid steam withdrawal. I

The foaming of boiler water is actually a rapid expansion of the Water in the steam generating area of the boiler brought about by the fact that rapidly forming small steam bubbles do not myriads of bubbles u t e thu ormed ocalled light wa r fills e e m space and fatty ae i ppl at o, Se al Ne- %2, ew U- S- en 2346 530; ssue Fe a y 5 %9) or of polyalkylene polya nines having two primary r u .a vlaied w th a highe a ty acid app ication, serial 591 293); or o .a product havinc meleeutlar ei ht o at l ast one thous de ived y condensa ion of a polymerized hi e t acid m eu wi h a compou d s e e from the group consisting of the alkylene diamines, the polyallsylene polyamines, the a'l'kanol amines; the a'lkanol alkylene diamines, the al- 1; -o1-poly,a;l-kylene polyamines, and the condensation; products of two males of a dibasic aliphatic amine with one mole of a dibasic carboxylic acid (application. Serial No. 560,899, new U. s. Patent bio. 2,493,453, issued January 3, 1950); or of a compound having the formula in which Y represents a radical selected from the group consisting of the S03 and S04 radicals, R represents a hydrocarbon chain containing at least ten carbon atoms and R1 represents a hydrocarbon chain containing at least ten carbon atoms (application, Serial No. 568,202); or of a predominantly hydrophobic quaternary ammonium compound having the formula in which R represents a hydrocarbon chain con- 4 some few parts per million of boiler water. In general, from a trace to about twenty-five or about fifty parts per million of foam inhibiting compounds may be added to boiler water, preferably in combination with tannin. Additional foam inhibiting compounds'may be repeated as required to prevent foaming.

p A preferred method of adding the foam inhibiting compounds to boiler feed water comprises the incorporation of the efiective foam inhibiting ingredients in apowdered formula, the constituents of which cooperate in greater or less degree in increasing the efliciency of the foam inhibiting taining at least twelve carbon atoms, R1 represents a hydrocarbon chain containing at least twelve carbon atoms, R2 represents a hydrocarbon chain containing at least twelve carbon atoms, and R3 represents a hydrocarbon chain containing from one to eleven carbon atoms and Hal represents a halogen atom (application, Serial No. 568,203); or of a secondary aliphatic amine having the general formula in which R. and R1 represent hydrocarbon chains each containing at least ten carbon atoms, at least one of said hydrocarbon chains being straight (application, Serial No. 568,204 now abandoned) or of a tertiary aliphatic amine having the general formula V RlTI--Rz in which It represents a hydrocarbon chain containing at least ten carbon atoms, R1 represents another hydrocarbon chain containing at least ten carbon atoms, and R; represents a hydrocarbon chain, at least one of the hydrocarbon chains R and R1 being straight (application, Serial No. 568,205 now abandoned) or of a compound having. the general formula .in which R. represents a hydrocarbon chain con- .taining at least twelve carbon atoms, R1 represents a hydrocarbon chain, and R2 represents a hydrocarbon chain containing at least eight carhon-atoms, at least one of the hydrocarbon chains R and R2 being straight (application, Serial No.

568,206); or of a compound having the general in which R represents a hydrocarbon chain containing at least twelve carbon atoms, and R1 represents a hydrocarbon chain containing at least twelve carbon atoms, at least one of said two hydrocarbon chains being straight (applica tion, Serial No. 568,207 or of other and further compounds disclosed or claimed in any one of the above identified applications and patents.

I have further disclosed in said patents and applications that the above indicated foam inhibiting compositions may be introduced into steam boiler water in the form of colloidal dispersions that may be stabilized with tannin, gum arabic or pectin. If desired, the foam inhibiting compositions may be introduced into the boiler in the form of a solution in an appropriate solvent, such as isopropyl alcohol. The dosages required are generally quite small, on the order of effect. Such formulae may be added manually directly to the locomotive tender, or the powder may be dissolved in water in mixing vats and sub- .sequently pumped into feed water storage tanks in specific proportions with the feed water to obtain uniform treatment of the Water. The following are examples of such powdered formulae:

, 7 Per cent 1. A'reaction product of ethylene diamine and 12-palmitate-Q-octadecenoic acid, in

a mole ratio of 1:4 2 Tannin (chestnut oak) 40 Tannin (quebracho) 4 Soda ash 53, Sodium hexametaphosphate 0.5 Chrome alum 0.5

2. Dioleyl amide ofethylene diamine'. 1.5

Tannin 45 'Lanthanum chloride 0.5 Tartaric acid 0.5

Soda ash 52.5

. Reaction products of ethanol triethylene tetramine and the fatty glycerides, such as soy bean oil, in a mole ratio 1:5 2.5 Tannin 45 Manganese glutamate 0.5 Saccharic acid 0.5 .Soda ash 51.5

. Condensation products (1:1 mole) of tetra-ethylene pentamine and peanut oil further condensed (1:1 mole) with oleic acid v V 5 Soda ash 51 Tannin (quebracho) 4 Tannin (chestnut) -l 40 It will be noted that the above disclosed compositions include tannin. The amount of tannin used may vary from about 5 to about times of the amount of the particular organic foam inhibiting compounds employed, and serves to render these organic foam inhibiting compounds more eflicient and to prolong their effective lives.

of, redwod bark dust or alkali derivatives of redwood bark.

Other and further objects and features of this invention will become apparent from the following description and appended claims.

i The nature and composition of the above mentioned redwood bark compositions are disclosed in an article entitled Chemical Composition of Redwood Bar by H. F. Lewis et a1. published in the August, 1944, issue of Industrial and Errgineering Chemistry, volume 36, pages 762 to 764. As disclosed in said article, large amounts of redwood bark waste normally result from lumbering operations in the western States, The bark of the redwood tree (at least that. part brought in from the woods for conversion into lumber) is a dense, somewhat fibrous material ranging in thickness from an inch or less up to ten inches or more. When the bark is run between milling rolls, the materials forming and lining. the 'cell wall structures disintegrate to form an amorphous powder, commonly referred to as "bark dust or "bark sand, which can be separated from the fibrous materials contained in the bark. For instance, the bark slabs from the peeling plant can be run through milling rolls to loosen the bark stru cture, with the subsequent formation of large matted fibrous bundles. This heterogeneous product is then subjected to textile cleaning and carding operations. A large percentage of the fiber is obtained as a loose fill insulation in fairly clean fiber bundles possibly one to two inches long. These bundles still retain some of the original bark structure and composition. The remainder of the fibers is separated from the bark dust as cleaned textile fiber approximately one-quarter to threequarters inch in length, with the fiber bundles well separated into what appear to be isolated fibers. Each filament, however, consists of sev-- eral ultimate bark fibers intertwined into a characteristic corkscrew structure. The greater share of the bark dust is taken from the condensers during the textile operation and at the present time is burned for lack of a better use. At least half of the weight of the bark is lost as dust in this stage of the operation.

The bark dust obtained as described above or by other methods may be used as obtained for the purpose of my present invention by incorporation with boiler water in amounts ranging from about five to one hundred times the amount of the organic foam inhibitor employed. This dust is made up of broken fibers, small cells, and the powdered walls of dead parenchyma cells and sieve cells, together with the dried contents of these and the cork cells. If desired, the bark dust may be extracted with alcohol, which removes 1.5% of the dust, including the tannin content thereof. Such alcohol extraction leaves a solid residue which I have found very suitable for the purposes of the present invention.

The bark dust may also be prepared for use in combination with organic foam inhibitors for water conditioning by treatment with solutions of sodium hydroxide or like alkalies. For instance, one part by weight of bark dust may be digested with 3.5 parts by weight of a solution containing 0.3 part by weight of sodium hydroxide at a temperature of approximately 150 C. for a few hours, or until about 88% of the bark dust becomes soluble or colloidally dispersible in water. The digested bark dust, after an optional removal of insoluble matters, such as fibers, by filtration or otherwise, is subjected to an evaporation process to remove the water, and the residue is then ground for admixture to a powdered formula in a manner similar to tannin, or, the dried digested bark dust may also be added separately to the boiler feed water, either alone or in conjunction with basic water softening chemicals such as soda ash or caustic soda. Further, such a sodium redwood bark dust may be admixed With various percentages of tannin, to better inhibit encrustation of calcium salts in feed water heaters and feed water pumps or the like.

If desired, such. preparation of the sodium derivative of redwood bark dust may be preceded by an extraction of the redwood bark dust with alcohol.

' Materials useful according to the present invention may also be prepared by similar digestions with sodium hydroxide, potassium hydroxide, soda ash or the like of the redwood bark fiber, or of disintegrated redwood bark. The concentration of sodium hydroxide may vary from one to twenty percent, or more, and the temperature of digestion may suitably be from to C. The time of digestion may vary from one to five hours, or sufiicient time to render from about thirty-five to about eightyeight percent of the digested material watersoluble or water-dispersible. Extraction with alcohol may precede such digestion.

In general, the sodium derivatives of redwood bark, redwood bark dust and redwood bark fiber may be prepared by any suitable method of digestion with aqueous sodium hydroxide or the like at temperatures above 100 C. continued until a substantial portion of the material has been rendered water-dispersible or water-soluble, the digestion, if desired, being carried out under super-atmospheric pressure. On a large scale, I prefer to use a jacketed digester where the heat is produced by steam pressure. A rotary digester is very satisfactory for this purpose since it can be discharged easily. At the end of a digestion period, the entire digester charge is dried in some convenient drying system, and the dried product is ground.

As indicated in the above identified article, the sodium salt formed by the digestion treatment disclosed appears to be a derivative of a lignin-like material easily soluble in dilute alkaline solutions and containing little if any methoxyl, but significant percentages of tree carboxyl and phenolic hydroxyl groups. Apparently redwood bark and its constituent parts (redwood bark dust and redwood bark fiber) contain large quantities of high molecular weight phenolic acids related to lignin and resembling humic acid in many ways. This acidic material, I believe, may be one of the active constituents of redwood bark for the purposes of the present invention, either as dissolved out or hydrolyzed out of redwood bark dust when added to boiler water (which as a rule is alkaline) or after digestion with alkali.

Very successful results have been obtained by adding redwood bark dust, the sodium derivative of redwood bark dust, the sodium derivative of redwood bark fiber, or the sodium derivative of redwood bark, in finely ground condition, to boiler water, for instance, in the ratio of one pound of redwood bark dust or other material to about 2,500 to 25,000 gallons of boiler water, in conjunction with a simultaneous use of from a trace to fifty parts per million of an alkylene diamine or alkylene polyamine acylated with a higher fatty acid. More particularly, I may use an ethylene diam-inc or a polyethylene polyamine acylated with a fatty acid containing at least twelve and preferably at least sixteen carbon .a'tQmasuch-as oleic acid,- stearic acid, lauric acid,

:palmitic acid, ricinoleic acid, and the like. In

the case of ethylene diamine, both amino groups should be acylated. In the case of polyalkylene poly'amines, both primary amino groups should preferably be acylated, and one or more of the secondary amino groups may also be acylated. Specific examples of ethylene diamines and diamides include dioleyl ethylene diamine, distearoyl ethylene diamine, dipalmityl ethylene diamide, and diricinoleyl ethylene diamide. Examples of derivatives of polyalkylene polyamine are the oleyl, stearoyl, palmityl, ricinoleyl, and linoleyl dior tri-derivativesof diethylene triiamine, triethylene tetra-amine, tetra-ethylene pentamine, and the like. The corresponding derivatives of lauric acid may also be employed. More than one higher fatty acid may be employed in the preparation of any one of these polyalkyl= ene polyamine and alklene diamine derivatives.

Very-good results have been obtained by the concurrent addition to alkaline locomotive boiler water of the above disclosed redwood bark dust or redwood bark alkali derivatives and the diamide of ethylene diamine with the fatty acids of soy bean oil or polymerized fatty acids of soy bean oil (as disclosed in my application, Serial No.-560,899). These and other-polyamides of aliphatic amines with higher acids may, if desired, be incorporated with redwood bark dust or alkali derivatives of redwood bark by being sprayed, in liquid condition, onto redwood bark dust or alkali derivatives of redwood bark, preferably followed by heating at approximately 100 C; for a short time to favor-absorption of polyamide by the sodium bark dust.-

When redwood bark dust, or alkali derivatives of redwood bark, are used perse for the purpose of lessening or preventing encrustation or scale formation due to deposition of insoluble calcium or magnesium compounds, the redwood bark dust or the alkali redwood bark derivatives,-may be added in amounts varying from one pound per 2,500 gallons of boiler'water to one pound per 25,000 gallons of boiler water.- At these concentrations,the calcium or magnesium compounds will be inhibitedin their normal tendency 'to deposit on physical surfaces, such as on surfaces of metals comprising feed water pumps, injectors, pipes, etc. r

The methods and compositions ofthis application are particularly applicable to the treat ment of water used in the generation ofhigh pressure steam, for instance, in locomotives, where the generated steam pressure may exceed one hundred or two hundred pounds per square inch. I 1 Many details of procedure and composition may be varied within a wide range without de parting from the principles of this invention and it is, therefore, not my purpose'to limit the patent granted on this inventionotherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. The method of generating steam from a boiler water having 'a tendency to foam on boiling which comprises dispersing into said water ethylenediamine diacylated with a fatty acid containing at least twelve carbon atoms in an effective amount up to 50 parts per million of boiler water, together with asubstan'c'e selected from the group consisting of redwood bark dust, a water dispers- 'ible alkali derivative of redwood bark dustja water dispersible alkali derivative of redwood bark fiber, and awater" dispersible alkali deriva- -t'iv'e of redwood bark, in an amountequivalent to 8 a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boiler water, and heating the resulting aqueous dispersion to the boiling point, the substances dispersed into said water functioning to inhibit the tendency of said water to foam on boiling.

2. The method of generating steam from a boiler water having a tendency to foam on boiling which comprises dispersing into said water a polyethylene polyamine acylated with at least two moles of a fatty acid containing at least twelve carbon atoms for each mole of said polyethylene polyamine in an effective amount up to 50 parts per million of boiler water, together with a substance selected from the group consisting of redwood bark dust, a water dispersible alkali derivative of redwood bark'dllst, a water dispersible alkali derivative of redwood bark fiber, and a water dispersible alkali derivative of redwood bark, in an amount equivalent to a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boileg; water, and heating the resulting aqueous dispersion to the bOiling point, the substances dispersed into said water functioning to inhibit the tendency of said water to foam on boiling.

3. The method of generating steam from a boiler water having a tendency to foam on boiling which comprises dispersing into said water a polyethylene polyamine diacylated with a fatty acid containing at least twelve carbon atoms in an effective amount up to 50 parts per million of boiler water, together with a substance selected from the group consisting of redwood bark dust, a. water dispersible alkali derivative of redwood bark dust, a water dispersible alkali derivative of redwood bark fiber, and a water dispersible alkali derivative of redwood bark in an amount equivalent toa ratio of one pound of the red-wood bark material for every 2500 to 25,000 gallons of boiler water and heating the resulting aqueous dispersion to the boiling point, th substances dispersed into said water functioning to inhibit the tendency of said water to foam on boiling.

4. The method of generating steam from a boiler'water having a tendency to foam on boiling which comprises dispersing into said water a polyethylene polyamine whose primary amino groups are acylated with a fatty acid containing at least sixteen carbon atoms in an effective amount up to 50 parts per million of boiler water, together with a substance selected from the group consisting of redwood bark dust, a water dispersible sodium derivative of redwood bark dust, a water dispersible sodium derivative of redwood bark fiber, and a water dispersible sodium derivative of redwood bark, in an amount equivalent to a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boiler water and heating the resulting aqueous dispersion to the boiling point, the substances dispersed into said water functioning to inhibit the tendency of said water to foam on boiling.

5. The method of generating steam from a boiler water having a tendency to foam on boiling which comprises dispersing into said water ethylene diamine whose primary amino groups are acylated with a fatty acid containing at least sixteen carbon atoms in an effective amount up to 50 parts per million of boiler Water, together with a substance selected from the group consisting of redwood bark dust, a water dispersible sodium derivative of redwood bark dust, a water dispersible sodium derivative of redwood bark fiber, and a water dispersible sodium derivative of redwood bark, in an amount equivalent to a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boiler water and heating the resulting aqueous dispersion to the boiling point, the substances dispersed into said water functioning to inhibit the tendency of said water to foam on boiling.

6. A composition adapted to be dispersed into a boiler water having a tendency to foam on boiling and, when so dispersed, functioning to inhibit said foaming tendency, said composition comprising ethylene diamine acylated with at least two moles of a fatty acid containing at least twelve carbon atoms in an efiective amount up to 50 parts per million of boiler water and a substance selected from the group consisting of redwood bark dustja water dispersible alkali derivative of redwood bark dust, a water dispersible alkali derivative of redwood bark fiber, and a water dispersible alkali derivative of redwood bark, in an amount equivalent to a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boiler water.

7. A composition adapted to be dispersed into a boiler water having a tendency to foam on boiling and, when so dispersed, functioning to inhibit said foaming tendency, said composition comprising a polyethylene polyamine acylated with at least two moles of a fatty acid containing at least twelve carbon atoms for each mole of polyalkylene polyamine in an effective amount up to 50 parts per million of boiler water, and a substance selected from a group consisting of redwood bark dust, a water dispersible alkali derivative of redwood bark dust, a water dispersible alkali derivative of redwood bark fiber, and a water dispersible alkali derivative of redwood bark, in an amount equivalent to a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boiler water.

8. A composition adapted to be dispersed into a boiler water having a tendency to foam on boiling and, when so dispersed, functioning to inhibit said foaming tendency, said composition comprising a polyethylene polyamine acylated with at least two moles of a fatty acid containing at least sixteen carbon atoms for each mole of said polyalkylene polyamine in an effective amount up to parts per million of boiler water and a substance selected from the group consisting of redwood bark dust, a water dispersible alkali derivative of redwood bark dust,

a water dispersible alkali derivative of redwood bark fiber, and a water dispersible alkali derivative of redwood bark, in an amount equivalent to a ratio of one pound of the redwood bark material for every 2500 to 25,000 gallons of boiler water.

LEWIS O. GUNDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,892,857 Spellmeyer Jan. 3, 1933 2,304,805 Denman Dec. 15, 1942 2,345,632 Robinson et al Apr. 4, 1944 2,372,797 Segessemann et a1. Apr. 3, 1945 FOREIGN PATENTS Number Country Date 12,161 Great Britain of 1892 547,189 Great Britain Aug. 18, 1942 

1. THE METHOD OF GENERATING STEAM FROM A BOILER WATER HAVING A TENDENCY TO FOAM ON BOILING WHICH COMPRISES DISPERSING INTO SAID WATER ETHYLENE DIAMINE DIACYLATED WITH A FATTY ACID CONTAINING AT LEAST TWELVE CARBON ATOMS IN AN EFFECTIVE AMOUNT UP TO 50 PARTS PER MILLION OF BOILER WATER, TOGETHER WITH A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF REDWOOD BARK DUST, A WATER DISPERSIBLE ALKALI DERIVATIVE OF REDWOOD BARK DUST, A WATER DISPERSIBLE ALKALI DERIVATIVE OF REDWOOD BARK FIBER, AND A WATER DISPERSIBLE ALKALI DERIVATIVE OF REDWOOD BARK, IN AN AMOUNT EQUIVALENT TO A RATIO OF ONE POUND OF THE REDWOOD BARK MATERIAL FOR EVERY 2500 TO 25,000 GALLONS OF BOILER WATER, AND HEATING THE RESULTING AQUEOUS DISPERSION TO THE BOILING POINT, THE SUBSTANCES DISPERSED INTO SAID WATER FUNCTIONING TO INHIBIT THE TENDENCY OF SAID WATER TO FOAM ON BOILING. 